Runny nose, streaming eyes, bouts of coughing, the human rhinovirus causes up to 50 % of colds. But new research has found that it’s not the virus itself that causes the dreaded symptoms, but its ability to hijack some of our genes and cause a massive immune response.
To study the basic genetics of HRV and to find out what causes the common cold, scientists recruited healthy volunteers and made some of them, well less healthy by inoculating them with HRV. The rest were given a sham inoculation. Then at 8 hours and again at 48 hours after inoculation, cell scrapings were taken from the nasal passages so researchers could study the genetic changes using gene chip technology.
Common cold and genes
After 8 hours there were no significant changes in the specimens but after 48 hours scientists noted that more than 6,500 genes in the HRV samples were either up or down regulated. These genes were either making antiviral proteins or pro-inflammatory cytokines and it’s this overblown response that’s believed to lead to runny noses and all the other irritations cold sufferers endure.
Scientists hope the research will put them on the road to finding targets for novel therapeutics by this probing of the basic genetics of the common cold. Currently no matter what medicines we use to treat a cold, it still hangs round for days. Sure, there’s some alleviation from the affects of some of the symptoms, but for many people, once a cold has gone away, a new infection will surface in a few months time.
The research was carried out by scientists from the Department of Physiology and Biophysics at the University of Calgary in collaboration with the University of Virginia and the Proctor and Gamble Company. It has identified some candidate genes and host defence pathways that may become targets for drugs. Before that happens though, more research has to be conducted to clarify their role in the progression of the disease.
The benefits may not just be for cold sufferers. People with asthma and chronic obstructive pulmonary disease (COPD) could profit too. That’s because the rhinovirus is also a common pathogen in these conditions.